$75 to start now for hanna test kits, with an additional ~$1 per test beyond the initial 10 they come with compared to ~$20 for between 50 - 200 tests on salifert depending on the kit. If you're testing Alk, calcium, nitrate, and phosphate weekly with hannah you're adding about $16 / month to your running costs of your tank.
Fwiw, the nyos kits are actually quite accurate. For example, the people have tested the nitrate test and it shows +/- 1-2ppm of nitrate which is the same precision that hannah reports.